Until now, photons, or the mass-less particles that constitute light, were thought to not interact, but rather simply pass through each other, just two beams of luminescence during a laser-light show.

But according to the Harvard Gazette, scientists at the Harvard-MIT Center for Ultracold Atoms have improbably coaxed photons into hardened molecules you could, in fact, whack against each other in, say, a Bespin-based duel-to-the-death resulting in one person, sadly, losing a hand. . . .